Method for cutting holes in roofing sheet material

ABSTRACT

Apparatus for punching holes in sheet material is provided. At least one cutting knife is mounted for rotation about a first axis. A punching surface of the knife includes end edges that protrude further from the axis than the side edges of the punching surface to permit the end edges to penetrate the sheet material before the side edges sever the sheet material. A cylindrical roll having a groove extending about its circumference is mounted for rotation about a second axis that is parallel to said first axis. The groove forms a pair of continuous cutting edges positioned in cooperative shearing relationship with the side edges of the punching surface of the knife. The new cutting method performed by the apparatus comprises first penetrating the sheet material with the end edges of the punching surface of the knife to form end cut lines which are longitudinally spaced in the sheet material, and then shearing the sheet material along a pair of side cut lines with each side cut line connecting a pair of laterally aligned ends of the end cut lines.

. ttes ihhing et al.

[ METHOD FOR (IUTTING HOLES IN ROOFING SHEET MATERIAL [75] Inventors: Edwin Ernst Hibbing, Castle Rock,

Colo.; Frank Preisler, South Bound Brook, NJ.

[73] Assignee: Johns-Manville Corporation,

Greenwood Village, C010.

22 Filed: Mar. 14,1974

21 Appl.No,:45l,663

Related [15. Application Data [62] Division of Ser. No. 287,117, Sept. 7, 1972, Pat. No.

[ Jan. 7, 1975 Primary ExaminerWillie G. Abercrombie Attorney, Agent, or Firm-Robert M. Krone; Stephen C. Shear [57] ABSTRACT than the side edges of the punching surface to permit the end edges to penetrate the sheet material before the side edges sever the sheet material. A cylindrical roll having a groove extending about its circumference is mounted for rotation about a second axis that is parallel to said first axis. The groove forms a pair of continuous cutting edgespositioned in cooperative shearing relationship with the side edges of the punching surface of the knife. The new cutting method performed by the apparatus comprises first penetrating the sheet material with the end edges of the punching surface of the knife to form end cut lines which are longitudinally'spaced in the sheet material, and then shearing the sheet material along a pair of side cut lines with each side out line connecting a pair of laterally aligned ends of the end cut lines.

. 2 Claims, 12 Drawing Figures Patented Jan. 7, 1975 6 Sheets-Sheet 1 Patented Jan. 7, 1975 3,858,469

6 Sheets-Sheet 2 H6: 3 F/G. 4

atented Jan. 7', 1975 6 Sheets-Sheet 5 UH mm 'HU rlll PM IL Patented Jan. 7, 1975 6 Sheets-Sheet 4 atented Jan. 7, 1975 6 Sheets-Sheet 5 afiented Jan. 7, 1975 6 Sheets-Sheet 6 METHOD FOR CUTTING HOLES IN ROOFING SHEET MATERIAL This is a Division of application Ser. No. 287,117, filed Sept. 7, 1972, now US. Pat. No. 3,813,977.

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to apparatus for cutting sheet material, and more particularly, to apparatus for cutting a plurality of distinct holes in roofing material ei ther before or after saturation of the material with asphalt or the like.

It is presently the practice to provide perforations in roofing sheet material so that air is not trapped by the roofing material as it is installed or as is formed into rolls for shipping or storing. Present methods for perforating webs of roofing material utilize a needle roll and an opposed grooved or wire brush roll. The insertion of the needles into the roofing creates perforations, but no roofing material is removed by the needles and, as a result, the holes in the roofing'material have a tendency to close up as the material is wound into rolls.

Because the needles do not remove any roofing material but merely poke through the material, the fibers of.

OBJECTS OF THE INVENTION It is, therefore, an object of the present invention to provide a method for forming a plurality of permanent and distinct holes in roofing or other sheet material by actually removing small amounts of material.

Another object of the invention is to provide a holecutting apparatus that is durable and easy to maintain.

Yet another object is to provide a method for perforating sheet material that is moving at rapid linear feed rates.

Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description or may be learned by practice of the invention. The objects and advantages are realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

SUMMARY OF THE INVENTION material comprising knife means mounted for rotation about a first axis. A punching surface is provided on the knife means that has the shape of the desired hole. The punching surface of the knife means includes end edges that protrude further from the axis than the adjacent portion of the side edges of the punching surface to permit the end edges to penetrate the sheet material before the portions of the side edges adjacent the end edges sever the sheet material. A cylindrical roll having a groove extending about its circumference is mounted for rotation about a second axis that is parallel to the first axis. The groove forms a pair of continuous cutting edges positioned in cooperative shearing relationship with the side edges of the punching surface of the knife for shearing the sheet material. The knife means and the grooved roller thus form a plurality ofdistinct holes in the sheet material as the material is fed between the knife means and the grooved cylindrical roll.

In a preferred embodiment, the knife means comprises a shaft mounted for rotation about the first axis and a plurality of knifeholding collars. The collars are concentrically mounted on the shaft for axial movement relative to the shaft. A plurality of cutting knives are mounted on the knife-holding collars. Holding means, such as a key and set screws are provided for fixing the rotational and lateral position of the knifeholding collars with respect to the shaft. This segmented roll arrangement, with the collars being axially movable along the shaft, insures that an individual knife can be easily removed from the knife means and replaced, if the knife becomes dullv or is broken in use.

It is desirable for ease of removal of the knife and particularly the punching surface :from the perforated sheet material that the rear surface of the knife extend from the back end edge of the punching surface towards the cylindrical surface of the knife-holding collar on which it is attached in the general direction the knife is rotatingduring the cutting operation. Specifically, the rear surface of the knife is desirably planar, and the plane of this surface intersects the cylindrical surface of the knife-holding collar on which the knife is attached at an angle of from 50.90 with respect to a plane tangent to the line of intersection of the plane of v the knife rear surface and the cylindrical surface of the knife-holding collar.

The invention also provides a method of cutting holes in roofing sheet material comprising the steps of con: tinuously feeding a web of sheet material in a given longitudinal direction; severing the moving sheet material along a pair of laterally-spaced longitudinallyextending lines. Each of the longitudinally-extending shear lines connects a pair of laterally aligned ends of the laterally extending lines so that a two-dimensional shape is severed from the sheet of material every time a severing and subsequent shearing operation is performed.

The accompanying drawings, which are incorporated 'in and constitute a part of this specification, illustrate examples of perferred embodiments of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF TI-llE DRAWINGS FIG. 1 is an elevation view of an embodiment of the apparatus of this invention.

FIG. 2 is a perspective view of cutting and calendering sections of the apparatus of FIG. 1.

FIG. 3 is a perspective view of a knife constructed in accordance with a preferred embodiment of this invention.

FIG. 4 is an end view of the knife of FIG. 3.

FIG. 5 is an elevation view of a knife-holding collar with a single knife mounted thereon.

FIG. 6 is an end elevation view of the knife-holding collar and the knife of FIG. 5.

tionship of these cutting elements to sheet material being cut.

FIG. is a plan view of sheet material illustrating the rectangular perforations formed by the preferred embodiment of the knife means as illustrated in FIGS. 35.

FIG. 11 is an end elevation view of one of the roll sections that form the grooved roll illustrated in FIG. 2; and

FIG. 12 illustrates another embodiment of the knife means of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference now to the drawings, wherein like reference characters designate like or corresponding parts theroughoutthe several views, there is shown in FIG. 1 means for saturating roofing sheet material with asphalt or the like. As here embodied, the saturating means includes one or more conventional saturators 10 provided with a roller 12 for guiding the roofing sheet material 14 toward first drive means generally 16. Drive means 16 are conventional and, as illustrated, include drive rollers 18 and 20 for removing sheet material 14 from saturators 10 and for directing the sheet material into cutting section 22 and into calendering section 24 of the apparatus. The structural details of the cutting and calendering sections are illustrated in more detail in FIGS. 29.

Calendering section 24 follows cutting sections 22 and is preferably comprised of two or more rolls 26 that may be heated. Springs 28 and 29 or other conventional means may be used for varying the pressure applied to sheet material 14 as it passes through the cutting and calendering sections, respectively. The cutting section and the calendering section also may each have conventional air lift cylinders (not shown) for ease of threading the sheet material through the cutting and calendering sections. The cutting and calendering sections are preferably mounted on a self-standing table 30.

Second drive'means generally 32 of conventional construction and including rollers 34 cause sheet material 14 to move first through cutting section 22 and then through calendering section 24. As here embodied, conveyor means-are also provided for receiving the sheet material from second drive means 32 and preferably for forming sheet material 14 into a plurality of overlapping loops. The conveying means may include a conventional looper conveyor 38 upon which the loops are formed and retainer surface 39 cooperating with the conveyor to generate the loops.

In accordance-with the apparatus of the invention, knife means are mounted for rotation about a first axis. The knife means include a punching surface having end edges that protrude further from the axis than the side edges of the punching surface to permit the end edges to penetrate the sheet material before the side edges contact the sheet material. As here embodied, and as shown in FIG. 2, the cutting section preferably includes a plurality of cutting knives 44 (illustrated in detail in FIGS. 3-5) mounted on a plurality of knife-holding collars 40 for rotation about a first axis defined by the axis of a shaft 42. As described in more detail below, the end edges of the punching surface of knives 44 protrude further from the axis of shaft 42 than the side edges of the punching surface.

In accordance with the invention, a cylindrical roll having a groove extending about its circumference is mounted for rotation about a second axis that is parallel to said first axis. The groove forms a pair of continuous cutting edges positioned in cooperative shearing relationship with the side edges of the punching surface of the knife for shearing the sheet material. As here em bodied, a grooved cylindrical roll generally 45 includes a second shaft 46 mounted for rotation about its own axis, and aligned parallel to shaft 42. A plurality of roll sections 48 are fixedly mounted on second shaft 46 for rotation therewith as illustrated in FIG. 2.

Each roll section 48 is precisely undercut at one end to form a groove with the adjoining end of the adjacent roll section. Thus, the undercuts form a plurality of grooves having edges 50, as illustrated in FIG. 9, that cooperate with one or more knives 44 for shearing sheet material 14 and for forming a plurality of distinct holes in the sheet material as the material passes between cylindrical roll 45 and cutting knives 44. As best illustrated in FIG. 9, each roll section 48 includes a cylindrical member 52'that is undercut at one end to form a cylindrical projection 54 of smaller diameter that extends axially from one end of cylindrical member 52. With reference to FIG. 11, a bore 56 and keyway 57 extend axially through each roll section 48 for enabling each roll section to be mounted on second shaft 46 as shown in FIG. 9. The roll sections are fixed on shaft 46 by a key 59, and set screws 61 that extend through openings 71.

The presently preferred construction of the knife means includes a shaft, knife-holding collars mounted on the shaft, cutting knives mounted on these collars,

. and holding means for fixing the rotational and lateral position of the knife-holding collars with respect to the shaft, and will now be described in detail. With reference to FIG. 12, the holding means includes a plurality of spacer collars 58 that are mounted on shaft 42 with a pair of axially spaced spacer collars 58 positioned between each pair of knife-holding collars 40. The spacing between the spacer collars permits axial movement of the spacer collars to permit access to remove the cutting knives from the knife-holding collars.

Each knife-holding collar 40, as illustrated in FIGS. 5 and 6, includes an outer cylindrical surface 60 and two faces 62 which extend in perpendicular relationship with respect to outer surface 60 and with respect to the axis of the cylindrical surface. An alternate arrangement of knife-holding collars 40 and spacer collars 58 is illustrated in FIG. 2, in which knives 44 are attached on only one face of each knife-holding collar 40.

As here embodied, the knife means also includes fastening means for attaching a plurality of knives 44 to each collar 40. The fastening means include a plurality of threaded holes 64 formed in each of the faces 62 (illustrated in FIGS. 5 and 6) for receiving Allen screws 65 or other fastening means so that knives 44 can be secured to collars 40. Each collar 40 includes a centrally-locatecl bore 66 for mounting the collar on shaft 42. A keyway 67 and a pair of drilled and tapped openings 69 are provided in each collar 40 for the insertion of a key (not shown) and a pair of set screws (not shown), respectively, to fox the collar in place on shaft 42.

Spacer collars 58 are constructed as shown in FIGS. 7 and 8. Each of the spacer collars defined an outer cylindrical surface 68 of the same diameter as surface 60 of collars 40. A centrally-located bore 70 for receiving shaft 42 extends axially of cylindrical surface 68. One face of each collar 58 is recessed, and includes a ring shaped center area 72 and an outer shoulder 80 that defines an annular ring.

Each spacer collar 58 also includes a keyway 8i and a two orthogonally-positioned screw-receiving threaded apertures 78 that extend radially inwardly from cylindrical surface 68 towards bore 70. The apertures enable the insertion of a key (not shown) and set screws (not shown) or other fixing means to hold the spacer collars on first shaft 42.

When knife-holding collars 40 and spacer collars 58 are mounted on shaft 42, as illustrated in FIGS. 2 and 9, two spacer collars 58 are positioned between each pair of knife-holding collars 40. Each spacer collar 58 is provided with an indented ring'shaped area 72 so that the screws 65 or other fastening means that hold knives 44 onto collars 40 can extend into the indented face of collars 58 (see FIG. 9). A pair of spaced spacer collars 58 are used between each knife-holding collar 40 to permit axial movement of the spacer collars and to enable the replacement of a worn or broken knife.

In assembling cutting section 22 of the apparatus, knives 44 are mounted onto knife-holding collars 40 by Allen screws 65. The number of knives mounted onto each collar is determined by the number of holes that are to be cut into the sheet material per longitudinal foot of material. If a large number of holes per unit length of sheet material are to be cut, more knives must be mounted on each collar 40 than if a smaller number of holes per unit length of sheet material are to be cut. Collars 40 and pairs of spacer collars 58 are then alternately positioned on shaft 42 with the exposed side face of each knife 44 jammed into tight abutting relation ship with shoulder 80 of a collar 58. Spacer collars 58 are affixed to shaft 42 by a key (not shown) and set screws (not shown). Knife-holding collars 40, and therefore knives 44 mounted thereon, are also held in both lateral and rotational alignment with shaft 42 by a key (not shown) and set screws (not shown) that extend along the apertures illustrated in FIGS. 5 and 6.

As best illustrated in FIG. 9, roll sections 48 and shearing edges 50 are precisely laterally positioned on shaft 46 to form grooves 82 for receiving the knives, with edges 50 positioned to cooperate with the knives to shear spaced longitudinal lines of short length on the roofing sheet material 14 passing between the knife means and grooved roll 45. It should be understood, of course, that instead of providing a plurality of roll sections 48, a single roll with a plurality of sharp-edged grooves formed therein could be used.

It is an important feature of the present invention that the knife means provide a punching surface in which the end edges of the surfacesprotrude further from the axis of revolution of the knife means than the side edges of the punching surface so that the end edges penetrate the sheet material before the side edges sever the material. This punching surface design, in combination with the grooved roller described above, insures a sharp cutting action and the severance of small areas of the sheet material from the web. The cutting action produced by the combination minimizes the tendency to merely displace or disturb fibers, as opposed to cutting them, even when the web of material is being fed at a high linear rate of speed.

A presently preferred design for knives 44 as illustrated in FIGS. 3 and 4. Each knife includes a shank 84. A forward from surface 92 extends rearwardly from the forward edge 88 of shank 84 with respect to the direction of rotation of the knife on the apparatus.

In preferred embodiments, and as illustrated in FIG. 3, a cutting tip 94 of tungsten carbide or other hard material is affixed to shank 84, which can be of mild steel, by a weld or other fastening means. The selection of other materials of construction for the shank and tip of the knife is within the skill of the art. For example, knife 44 may comprise a single piece of steel, if the life of the cutting edge is not a criteria of prime importance.

As illustrated in FIG. 3, a punching surface 96 is pro vided that has the approximate shape and area that is desired for the perforation to be formed in sheet material 14. The punching surface is defined by a forward end edge 102, a rear end edge 104, and a pair of arcuate side edges 105.

Shank 84 includes circular apertures 106 for en abling the knife to be fastened to knife-holding collars 40. In the illustrated embodiments, and as shown in FIG. 5, the axes of the apertures in shank 84 are aligned with the axes of a pair of threaded. holes 64 that are radially spaced along a radius line 107 on knife-holding collar 40.

When a knife 44 is attached to a collar 40, as illustrated in FIG. 5, leading end edge 102 and trailing end edge 104 each protrude further from the axis of the shaft on which the collar 40 is mounted than the portions of the side edges 105 of the punching surface 96 that are adjacent the respective end edges. Thus, punching surface 96 towards the cylindrical surface 60 of knife-holding collar 40 on which knife 44 is attached in the direction the knife is rotating during cutting operations, to permit easy withdrawal of knife 44 from the material being perforated.

The plane of rear surface desirably intersects the cylindrical surface 60 of knife-holding collar 40 on which knife 44 is attached at an angle of from 50-90 with respect to a plane 122 tangent to the line of intersection of the plane of rear surface 120 and the cylindrical surface 60 of knife-holding collar 40. The plane of front surface 92 of knife 44 is preferably aligned approximately parallel to rear surface 120.

In operation of the apparatus illustrated in FIG. 1, sheet material 14 passes through saturators 10 in a conventional manner. It should be understood, however, that the apparatus is equally effective in acting upon sheet material before or after saturation.

The sheet material is then drawn over roller 12, for example, by first drive means 16, and passes over drive rollers 18 and 20 to be fed into cutting section 22 of the apparatus. The material then passes between (a) the segmented roll sections 48 (FIGS. 2 and 9). As material 14 moves ahead, shafts 42 and 46 are preferably driven to cause knives 44 to rotate about the axis of first shaft 42 and to cause shearing edges 50 to rotate about the axis of second shaft 46 in cooperative shearing relationship with the knives for cutting a plurality of distinct holes in the sheet material as it passes between knives 44 and shearing edges 50.

The construction of knives 44 permits distinct holes to be cut into sheet material 14. As each knife rotates about shaft 42, forward cutting edge 102 and rear cut ting edge 104 initially penetrate down through the sheet material. The knife continues to rotate about shaft 42 until side edges 105 shear the material in cooperation with edges 50. As the knife continues to rotate;

punching surface 96 protrudes through the horizontal plane of the sheet material and punches out the previously severed piece 108 of material as illustrated in FIG. 9, so that a distinct hole or slot is produced.

A plurality of knives 44 can be mounted circumferentially around each individual collar 40 depending upon the number of holes desired per unit length of material. In addition, the number of knife-holding collars 40 and the number of rolls 48 defining shearing edges 50 can be readily adjusted as determined by the width of the sheet material.

Because the pieces 108 cut from the sheet material may have a tendency to collect within groove 82 (FIG. 9), doctor blades 108 (FIG. 1) may be positioned to remove the severed pieces from grooves 82 as roll sections 48 rotate about shaft 46.

Sheet material 14 now having a plurality of holes 112 cut therein (as illustrated in FIG. passes from cut ting section 22 into calendering section 24 and between calendering rolls 26. The calendering section may be made up of two rolls, as illustrated, or more than two rolls may be used. The calendering rolls may be heated to enhance the calendering action.

Calendering rolls 26 flatten the fibrous material in sheet 14, and particularly in the areas immediately adjacent to the holes formed by the knives so that the material can be wound into compact rolls to save storage and shipping space. The calendering rolls also assist in withdrawing the sheet material from the cutting section and prevent sheet 14 from binding on knives 44 as the sheet material is withdrawn from the cutting section.

The flattened sheet material 14, still having a plurality of distinct holes therein, is then withdrawn from calendering section 24 of the apparatus by second drive means 32. The sheet material is then fed to a conventional looper section including conveyor 38 and retainer surface 39 where the sheet material is formed into a plurality of overlapping loops in a conventional manner.

This invention thus provides a unique apparatus for cutting-permanent and distinct holes into sheet material by rotating a plurality of knives about a first axis, rotating a plurality of shearing edges about a second axis parallel with the first axis, and by moving the sheet material between the knives and the shearing edges whereby a plurality of distinct holes are cut into the sheet material.

The invention in its broader aspects is not limited to the specific details shown and described, and departures may be made from such details without departing from the principles of the invention and without sacrificing its chief advantages.

What is claimed is:

1. A method of cutting holes in roofing sheet material comprising the steps of:

a. continuously feeding a web of sheet material in a given longitudinal direction;

b. penetrating the moving sheet material along a pair of longitudinally-spaced, laterally-extending lines at substantially the same time by means of an edged instrument which is rotated about a predetermined axis; and subsequently shearing the moving sheet material with said edged instrument along a pair of laterally-spaced, longitudinally-extending lines, each of said longitudinally-extending lines connecting a pair of laterally aligned ends of the laterally-extending lines.

2. The method of claim 1 in which the sheet material is fed in a horizontal direction, and the sheet material is penetrated by moving said edged instrument down through the sheet material, and including the step of passing the edged instrument downwardly through the plane of the sheet material to punch out a piece of sheet material defined by the pair of spaced laterallyextending lines and the laterally-spaced longitudinallyextending lines. 

1. A method of cutting holes in roofing sheet material comprising the steps of: a. continuously feeding a web of sheet material in a given longitudinal direction; b. penetrating the moving sheet material along a pair of longitudinally-spaced, laterally-extending lines at substantially the same time by means of an edged instrument which is rotated about a predetermined axis; and subsequently c. shearing the moving sheet material with said edged instrument along a pair of laterally-spaced, longitudinally-extending lines, each of said longitudinally-extending lines connecting a pair of laterally aligned ends of the laterally-extending lines.
 2. The method of claim 1 in which the sheet material is fed in a horizontal direction, and the sheet material is penetrated by moving said edged instrument down through the sheet material, and including the step of passing the edged instrument downwardly through the plane of the sheet material to punch out a piece of sheet material defined by the pair of spaced laterally-extending lines and the laterally-spaced longitudinally-extending lines. 